1. Field of the Invention
The present invention relates to the field of mucosa disease treatment.
2. Description of the Background Art
Oral ulcerative mucositis is a common, painful, dose-limiting toxicity of drug and radiation therapy for cancer. The disorder is characterized by breakdown of the oral mucosa that results in the formation of ulcerative lesions. In granulocytopenic patients, the ulcerations that accompany mucositis are frequent portals of entry for indigenous oral bacteria often leading to sepsis or bacteremia. Mucositis occurs to some degree in more than one third of patients receiving anti-neoplastic drug therapy. The frequency and severity are significantly greater among patients who are treated with induction therapy for leukemia or with many of the conditioning regimens for bone marrow transplant. Among these individuals, moderate to severe mucositis is not unusual in more than three-quarters of patients. Moderate to severe mucositis occurs in virtually all patients who receive radiation therapy for tumors of the head and neck and typically begins with cumulative exposures of 15 Gy and then worsens as total doses of 60 Gy or more are reached.
Clinically mucositis progresses through three stages:
1. Inflammation accompanied by painful mucosal erythema, which can respond to local anesthetics.
2. Painful ulceration with pseudomembrane formation and, in the case of myelosuppressive treatment, potentially life-threatening sepsis, requiring antimicrobial therapy. Pain is often of such intensity as to require parenteral narcotic analgesia.
3. Spontaneous healing, occurring about 2-3 weeks after cessation of anti-neoplastic therapy.
Standard therapy for mucositis is predominantly palliative, including application of topical analgesics such as lidocaine and/or systemic administration of narcotics and antibiotics. Currently, there is only one approved treatment for oral mucositis, Kepivance (Palifermin), which is only approved for the treatment of oral mucositis in patients undergoing conditioning regimens prior to hematopoetic stem cell transplantation for the treatment of hematologic malignancies.
The complexity of mucositis as a biological process has only been recently appreciated. It has been suggested that the condition represents a sequential interaction of oral mucosal cells and tissues, reactive oxygen species, pro-inflammatory cytokines, mediators of apoptosis and local factors such as saliva and the oral micro biota. While epithelial degeneration and breakdown ultimately result in mucosal ulceration, it appears that the early changes associated with radiation-induced mucosal toxicity occur within the endothelium, and connective tissue of the submucosa. Electron microscopic evaluation of mucosa within 1 week of radiation shows damage to both endothelium and connective tissue, but not epithelium. Such injury is likely mediated by free radical formation. It appears that the overall mechanism for mucositis development is similar for both radiation and chemotherapy.
There remains a need in the art for improvements in methods for treating or preventing mucosa diseases.